Greek Civil Protection Minister Mihalis Chrisohoidis says a bomb attack inside his ministry has killed one of his close associates.

Officials said the bomb, disguised as a gift, exploded on the seventh floor of the ministry, near Chrisohoidis’ office, on Thursday night. The minister was inside the building at the time but he was not harmed.

Chrisohoides said Thursday that the “cowardly murderers will be brought to justice.” He says he “lost a valuable and beloved associate.”